WILLIAM G Capacity, narrow profile, hip pockets, load transfer to hips, price is right and Sunny Sports shipped fast.

WILLIAM G You are correct, it is the 30(trim) and 35(regular). I'm 6' with a 36" waist the 35(regular) is what I own. I carried mine all over Yellowstone and Redwood parks and other than ALOT of extra strap on this thing I like it. The top is a bit floppy if you have a really light/not bulky load. I really like the hip pockets and narrow profile. This is a great pack when you're helping carry the majority of the little kids day hike picnic. When my son and I go climbing it works out great for rope and climbing gear.

WILLIAM G Measuring Your Torso To determine your torso length, measure the distance between the C7 vertebrae and the top of the hip bone. Then use the sizing charts to choose a pack that will best fit your body type. Unless you are wickedly "trim" I'd stick with the Regular fit packs. TECH SERIES HIGH SIERRA TECH PACKS TORSO MEASUREMENT WAIST MEASUREMENT PACK FIT LENGTH OF TRAVEL LIGHTNING 30 12-16 in. / 30.5-40.6 cm 26" and up Trim Day / Overnight LIGHTNING 35 13-17 in. / 33-43 cm 26" and up Regular Day / Overnight HAWK 40 14-18 in. / 33.5-45.7 cm 26" and up Trim Day / Overnight HAWK 45 15-19 in. / 33-48.2 cm (adjustable) 26" and up Regular Day / Overnight TITAN 55 13-18 in. / 33-45.7 cm (adjustable) 30" and up Trim Weekend TITAN 65 14-20 in. / 35.5-51 cm (adjustable) 30" and up Regular Weekend

Zack W For backpack sizing the Torso is the back side of the human body without the head and limbs, so the "Torso Fit Range" should be measured from the back of the neck to the top of your hipbone. You can follow the link bellow to get an idea of how to choose your correct size. Enjoy it! Zack. http://www.trailspace.com/articles/backpacks.html